Chair back



FIG. 1 is a front perspective view of a chair back showing my new design;

FIG. 2 is a bottom view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a left side view, the opposite side view being a mirror image, thereof;

FIG. 5 a front view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a back perspective view thereof. 

The ornamental design for a “chair back,” as shown and described. 